Outage analysis of cognitive energy harvesting relaying networks with opportunistic relay selection over nakagami-m fading channel

This paper studies the outage probability (OP) of cognitive decode-and-forward (DF) relaying networks with energy harvesting in the Nakagami-m fading channel. To ensure the reliability of the transmission, the cognitive transmitter (S) communicates with cognitive receiver (D) via the relay, which is selected from multiple relays based on an opportunistic relay selection strategy. The transmit power of S and relays are constrained by the maximum tolerable interference power on the multiple primary users (PUs). Two protocols of energy harvesting at relay, i.e., power splitting (PS) and time switching (TS) protocols are studied. We derive the OP of the cognitive DF relaying networks in PS and TS protocols, respectively and study the impact of the data rate, time switching rate, the fading coefficients, the number of PUs and relays on the cognitive networks. The Monte-Carlo simulations are provided to verify the correctness of our analysis results.